Nonwoven fabrics are used in a variety of different products, including absorbent articles such as sanitary products and disposable diapers, cleaning products such as wipers, and medical goods such as masks. The nonwoven fabrics used in such products usually have performance suited for the particular purposes of the products and their location of use.
With absorbent articles, for example, it is preferred for the nonwoven fabrics to be capable of expanding and contracting in response to bodily movement during wear or use, without creating an uncomfortable feeling for the user. With disposable diapers as well, it is preferred for the nonwoven fabrics to have high elasticity and strength sufficient to prevent tearing during extension, as well as satisfactory feel on the skin and air permeability.
The nonwoven fabrics having desired functions in such products are usually specially designed and produced for each product, and from the viewpoint of production cost and environmental protection, it is preferred for a nonwoven fabric having the desired performance to be one that can be easily produced by modification of a commercially available nonwoven fabric, for example.
In PTL 1, for example, where the aim is to provide a stretchable nonwoven fabric with further improved properties including stretchability, there is described a stretchable nonwoven fabric obtained by stretching a fiber sheet comprising an essentially nonelastic fiber layer made of continuous fibers formed by a spunbond method, on each side of an elastic fiber layer made of continuous fibers formed by a spunbond method, and then relaxing the tension to impart stretchability.
PTL 1 also states that the elastic fiber layer contains a thermoplastic elastomer.